Comparing Fingerling Potato Cropping Methods on No-Till Raised Beds

Final Report for FNE10-687

Project Type: Farmer
Funds awarded in 2010: $8,524.00
Projected End Date: 12/31/2010
Region: Northeast
State: Vermont
Project Leader:
Justin Hart
Whip Poor Will Farm LLC
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Project Information

Summary:

FNE10-687: Comparing Fingerling Potato Cropping Methods on No-Till Raised Beds
Justin Hart, Whip Poor Will Farm LLC, PO. Box 202 Jamaica Vt. 05343
(802)-874-8141, HartJustin6@gmail.com, 1/6/11

Summer 2010: We tested three fingerling potato cropping methods with the aim of finding the most efficient, highest yielding approach in producing organic fingerling potatoes on raised beds using a zone-till technique. Our beds average 300’ x 6’ x 1’6”, totaling two acres.

Our plan in brief: Compare yield, time, cost, energy, and soil fertility for three different production methods: fingerlings planted directly into Dutch white clover; fingerlings planted directly into Dutch white clover and rye; and fingerlings planted directly into Dutch white clover and mulched with rodeo oat straw grown in a grain swath parallel to our raised beds.

Introduction:

Our farm’s main focus is four to five cash crops grown in volume for organic, regional wholesale markets. One of the problems we face with wholesale level production is creating enough biological diversity to create a balanced agro-ecosystem as seen on smaller, more diversified farms. One way we achieve a certain level of pest management in a semi mono-cropping model is by using the Alley Cropping method. By design, we built our raised beds measuring 6’ in width, with 10’ alleyways. These alleyways are permanently cover cropped with the idea that beneficial insects and fungi will colonize providing a balanced biological system. Other benefits of this method insure foot and machine traffic stay off the permanently cropped beds thus reducing the need for deep tillage.

People involved in this study: Justin Hart, farmer and manager; Kate Muir, farmer; and Adam Hart, hired hand. Wendy Sue Harper, Ph.D. was our Technical Advisor.

Project Objectives:

Our plan in brief: Compare yield, time, cost, energy, and soil fertility for three different production methods:

• Fingerlings planted directly into Dutch White Clover.
• Fingerlings planted directly into Dutch White Clover and rye.
• Fingerlings planted directly into Dutch White Clover and mulched with oat straw grown in a grain swath parallel to our raised beds.

Cooperators

Click linked name(s) to expand
  • Wendy Sue Harper
  • Adam Hart

Research

Materials and methods:

Project Activities:

Before beginning our project, the beds were prepared by disk harrowing the fall prior to planting. Our soil test showed our soils were PH neutral and macro-nutrient deficient. NPK was added at 200lbs. per acre before planting. In early April, we sowed Dutch white clover on all the beds, while the top third of the field beds were planted in Dutch white clover and winter rye. All 10’ alley crops between the beds were planted in rodeo oats and white clover. The total seed used: 70 lbs white clover for 2.25 acres $472; 70 lbs winter rye for 3/4 of an acre $64; and 100 lbs of oats for one acre $200. Our total cost for cover crop seed planted on 2.25 acres was $736.

Our SARE grant provided us funds to purchase a single row transplanter. We thought seeding tubers with this method could reduce the need for extensive bed tillage. To our dismay this particular transplanter drop shaft was not large enough to accommodate the fingerling potatoes, causing varying seeding rates due to blockage. Beyond the technical problems, we feel a single row transplanter is inefficient in terms of labor, as one person is seeding while one is driving. Our method described below allows for two people to plant at the same time. We could possibly see the efficiency in multiple row seeders, but in our opinion, single row seeders do not increase labor efficiency for planting potatoes.

In May, cover crop density was relatively thin as germination was subpar due to a dry spring. Prior to planting, all beds were mowed with the DR Brush Mower; planting commenced on May 10th. All beds were planted in three rows measuring 18” on center x 1ft plant spacing. Rows were then precision chiseled using a buckeye chisel plow set to rip furrows 18” on center. 1,200 lbs of fingerling seed was then planted into the furrows, on average four inches deep. After, a chain harrow mounted on a welded frame—allowing us to lift the chain at the end of the rows—was used to cover the seed. This method worked great in its efficiency in planting: two people were able to plant two 1/4 acres in two and a half days. Although efficient in planting, the beds were severely compacted. Because we chose to plant three rows per bed we then had to harrow the soil back over the seed by driving one way up the bed with our tires following the outside row and straddling the middle row and the opposite coming back. In effect, we eliminated the gain from chiseling out the seeded rows and had no way to loosen the soil as our tire-width would not allow us to straddle all three rows to cultivate. From this point on we knew our yields would be less than average.

After planting we reseeded with white clover. Upon reseeding, we realized buckwheat—being a tender succulent—could be a great nurse crop for white clover, so we over seeded buckwheat on the bottom third of the beds. The potato seed started to shoot through roughly three weeks later. When the buckwheat grew to sufficient height around July 20th and then again on August 15th, we used a roto-tiller to shallow till the potato rows, minimizing the overgrowth and releasing the clover, allowing it to grow with more vigor.

After good germination, a healthy looking stand of potatoes grew to about six inches by June 20th. In late June - early July we started to see our first flush of potato beetles and, again, really dry, hot weather. Around July 20th we started to see significant die off without any flower.

Due to the combination of the aforementioned factors, we saw yields decline significantly. For 1,200 lbs seeded we received a total yield of 3,000 lbs, roughly ¼ of the projected yield. Yields per cropping method measured 1,500lbs. for bed planted with white clover and buckwheat, 800lbs for beds planted in white clover and 700lbs for beds planted in white clover and winter rye. All three planting methods measure roughly the same linear ft. planted. The average tuber set was ten per plant. The tuber size ranged from small to very small in size, indicating the plant died shortly after setting seed. Potato yields were weighed using 50 lbs. bags on a hanging scale.

Research results and discussion:

Results:

Winter rye should not be inter-planted with potatoes as it is prolific, uptakes a significant amount of water, and cannot be controlled by mowing. As a result it was labor intensive: a significant amount of hand weeding was done in an effort to save this crop.
No improvement in soil organic matter was recorded due to soil compaction. Micro nutrient levels, however, did improve due to the NPK added before planting.

Inter-planting white clover alone with potatoes is not sufficient in controlling perennial weeds. Presumably, white clover could provide sufficient weed suppression if over seeded in early spring into a winter killed cover crop, of oats.

Growth of the oats sown in the alleyways was not sufficient to provide mulch for the beds. This can be attributed to the lack of sufficient rainfall and soil fertility. Also, time and energy using the Alley Cropping method without appropriate equipment may be cost prohibitive as well as energy intensive. If growth of the oat crop was to reach sufficient heights this crop may have acted as a barrier inhibiting potato beetle movement.

There were nuggets of interest to be gleaned from our crop failure. The best yields and least amount of potato beetle pressure were seen in the rows inter-planted with buckwheat. Yields in these rows of 300 ft averaged closer to expected yields of 450 lbs per bed. These potato plants also maintained healthy foliage and growth until late August. Through observation, we noted buckwheat aided in creating a cooler surface microclimate while proving longer moister retention from the morning dew. Water up take was presumably not affected by the buckwheat as its succulent, shallow rooted nature did not interfere with the potato plant root zone. White clover growth was abundant in this cropping scheme as its ideal growth environment of cool, moist conditions was maintained by the buckwheat. Buckwheat is also easily controlled by mowing and—due to its succulence—decomposes quickly, reducing organic nutrient tie-up. Furthermore, buckwheat’s ample white flowers also seemed to attract many beneficial insects, such as the twelve-spotted ladybeetle and spined solider bug, aiding in controlling the potato beetles.

Economics:
Intercropping can be economically beneficial for commercial potato growers. The areas where this method can serve as a net benefit are as follows: First, although cover crop seed can be expensive, especially Dutch white clover, the advantages gained in soil structure and fertility can far out way this micro-investment when the macro-returns of soil fertility and structure is improved over time. Second, cultivation is traditionally the most fuel intensive endeavor in regard to potato cropping. Hilling potatoes requires significant horsepower and thus fuel. Mowing Buckwheat and clover in a single pass requires far less horsepower, thereby saving in fuel costs. We did not have the hilling equipment to measure the fuel use between these two methods; but we can report we used 8 gallons of gas for roto-tilling 2 1/4 acres twice over the summer. Third, intercropping buckwheat and white clover provides pest management by providing habitat for beneficial insects. Also, by reducing spraying to a spot spray, the farmer can save on fuel and insecticide costs. Chronic Colorado potato beetle resistance with regards to a specific insecticide could also be reduced. Fourth, defenses against blight could be improved by not exposing soil during hilling. As such, soil to leaf contact would be mostly eliminated, thus reducing the chance of soil born blight while improving the chance for beneficial fungi to colonize. Finally, I am optimistic that yields under this cropping method can be refined to the point where yields can compete or exceed traditional hilling methods. The reduced fuel inputs and increased yields could be of a net benefit to the farmer willing to adopt these methods. Yet, although this method shows promise, further research and refinement is needed before a definitive endorsement can be made.

Participation Summary

Education & Outreach Activities and Participation Summary

Participation Summary:

Education/outreach description:

Outreach: Many local farmers came to the farm throughout the cropping season to view and discuss our methods. However, because of the relative crop failure no large field days were scheduled.

Project Outcomes

Assessment of Project Approach and Areas of Further Study:

Future Recommendations

The purpose of our grant was to distinguish between three specific fingerling potato cropping methods. Intercropping with winter rye and white clover was a failure as winter rye is too hardy to simply control through successive mowing; winter rye must be tilled under before planting. However, intercropping with white clover and buckwheat is promising. Buckwheat is easily controlled with a single mowing, ideally once the potato plant reaches its regenerative state. The residual buckwheat plants provided beneficial insect habitat. As mentioned earlier, mowing also released the clover, allowing it to flourish, thereby providing adequate weed control. Again, the results of our potato harvest where subpar due to a combination of soil compaction and environmental factors—a dry hot summer and intense Colorado potato beetle pressure. As a result, our assessment of the project was inhibited by these factors. Yet, we are optimistic that we have hit on a unique intercropping method of field peas, white clover and buckwheat and look forward to improving these techniques in 2011.

The purpose of our grant was to distinguish between three specific fingerling potato cropping methods. Intercropping with winter rye and white clover was a failure as winter rye is too hardy to simply control through successive mowing; winter rye must be tilled under before planting. However, intercropping with white clover and buckwheat is promising. Buckwheat is easily controlled with a single mowing, ideally once the potato plant reaches its regenerative state. The residual buckwheat plants provided beneficial insect habitat. As mentioned earlier, mowing also released the clover, allowing it to flourish, thereby providing adequate weed control. Again, the results of our potato harvest where subpar due to a combination of soil compaction and environmental factors—a dry hot summer and intense Colorado potato beetle pressure. As a result, our assessment of the project was inhibited by these factors. Yet, we are optimistic that we have hit on a unique intercropping method of field peas, white clover and buckwheat and look forward to improving these techniques in 2011.

Potential Contributions

Our SARE grant allowed us to test potato cropping methods that may be considered unconventional. One thing we will do differently in 2011 is frost seeding a cover crop of field peas and white clover in early April. As field peas are quick to grow in early spring conditions, we believe they will provide an excellent nurse crop for the white clover. Field peas will be inoculated when planted and mowed before potato planting in order to release nitrogen, a limiting factor in potato production. We do realize field peas are a fairly expensive cover crop per acre, possibly rendering this method uneconomical. After planting we will over seed with white clover and buckwheat as we did in 2010. This method would give us a delayed potato planting of June 1st, hopefully mitigating the initial potato beetle flush, by delaying its food source. We believe this method, accompanied with reducing our bed rows to two rows per bed, could produce satisfactory results.

Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.